<template>
  <view>
    <my-search :bgcolor="'pink'" @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧滑动区 -->
      <scroll-view scroll-y="true" :style="{height: wh + 'px'}" class="left-scroll-view">
        <!-- <block/> 并不是一个组件，它仅仅是一个包装元素，不会在页面中做任何渲染，只接受控制属性 -->
        <block v-for="(item, index) in cateList" :key="index">
          <view :class="['left-scroll-view-item',  active === index ? 'active':'' ]" @click="activeChange(index)">
            {{ item.cat_name }}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧滑动区 -->
      <scroll-view scroll-y="true" :style="{height: wh + 'px'}" class="right-scroll-view" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, index2) in cateLevel2" :key="index2">
          <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
          <!-- 动态渲染三级盒子的列表数据 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3, index3) in item2.children" :key="index3" @click="gotoGoodsList(item3)">
              <image :src="item3.cat_icon"></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    mixins: [badgeMix],
    data() {
      return {
        // 当前设备可用屏幕高度
        wh: 0,
        // 分类列表
        cateList: [],
        // 激活编号
        active: 0,
        // 二级分类列表
        cateLevel2: [],
        scrollTop: 0
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {data: res} = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children 
      },
      activeChange(index) {
        this.active = index
        // 重新为二级分类赋值
        this.cateLevel2 = this.cateList[index].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      // 跳转到商品列表页面
      gotoGoodsList(item) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
  
  .left-scroll-view {
    width: 120px;
    
    .left-scroll-view-item {
      background-color: #F7F7F7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;
      
      // 表示当前元素的样式包含 .left-scroll-view-item 和 .active
      &.active {
        background-color: #FFFFFF;
        position: relative;
        
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #C00000;
          position: absolute;
          top: 50%;
          left: 0;
          transform: translateY(-50%);
        }
      }
    }
  }
  .right-scroll-view {
    background-color: #FFFFFF;
  }
}
  .cate-lv2-title {
      font-size: 12px;
      font-weight: bold;
      text-align: center;
      padding: 15px 0;
    }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
    
    .cate-lv3-item {
      width: 33.33%;
      display: flex;
      flex-direction: column;
      // 纵向居中
      justify-content: center;
      // 横向居中
      align-items: center;
      margin-bottom: 10px;
      
      image {
        width: 60px;
        height: 60px;
      }
      
      text {
        font-size: 12px;
      }
    }
  }
</style>
